“The United States Senate needs a leader like Jeff Flake,” Palin, the 2008 GOP vice presidential nominee, wrote in a letter to Flake. “Jeff is a proven conservative crusader, and today I am proud to announce my support for his campaign to become the next U.S. Senator from the great state of Arizona.”

Flake has found himself in a much tougher primary than expected against self-funded GOP rival Wil Cardon. A little more than a week ago, he picked up two other high-profile endorsements from the state’s two Senators, Kyl, the No. 2 ranking Senate Republican, and Sen. John McCain (R).

Former Surgeon General Richard Carmona is the presumptive Democratic nominee. Roll Call rates this race as Leans Republican.